Correlation of user equipment identity to information centric networking request

ABSTRACT

An access node ( 620 ) of the cellular network determines a correlation of an identifier of a user equipment ( 610 ) with an entry of a Pending Interest Table maintained by an Information Centric Networking node ( 670 ). The Pending Interest Table comprises an entry for each data object having a pending Information Centric Networking request ( 801 ) at the Information Centric Networking node ( 670 ). Based on the correlation, the access node ( 620 ) controls a connection of the user equipment ( 610 ) with the cellular network. This may involve deciding whether to release the user equipment ( 610 ) to idle mode or paging of the user equipment ( 610 ).

TECHNICAL FIELD

The present invention relates to methods for conveying data in acellular network and to corresponding devices and systems.

BACKGROUND

In networking, paradigms referred to as Information Centric Networking(ICN), Content Centric Networking (CCN), and Named Data Networking (NDN)have been developed. CCN and NDN may be regarded as specific approacheswithin the more general ICN paradigm. By way of example, CCN is beingdeveloped within IETF (Internet Engineering Task Force) by the ICNRG(ICN Research Group), and details on this work can be found in CCN asdefined in ICNRG Internet-Drafts “CCNx Semantics”, Version 01, January,2016, and “CCNx Messages in TLV Format”, Version 01, January 2016.

Instead of focusing on connecting communicating endpoints (astraditional networking protocols, such as IP (Internet Protocol), ICNfocuses on a content object to be retrieved. In ICN, networking messagesare routed based on globally unique names of content objects, ratherthan on endpoint addresses referring to physical boxes.

In this way, ICN may benefit from in distributing the same informationto multiple places in the network. Since routers may cache contentobjects besides forwarding them, content objects do not need to traversethe entire network every time someone becomes interested in them—a localcached copy suffices. Another advantage with ICN is the aggregation ofinterests for a given content object. For example, in the case of aflash crowd event where suddenly thousands of endpoints are requestingthe same content the source will only need to be reached by one requestfor the content, and all other requests may be served from the caches ofrouters along the path towards the source. Since these benefits is alsorelevant to cellular networks, it may be desirable to enhance a cellularnetwork with CCN/ICN capabilities.

However, enhancement of a cellular network with ICN/CCN capabilities isnot straightforward because in a cellular network an end device, alsoreferred to as UE (user equipment) may move between different accessnodes. Further, it is possible that the UE does not maintain a permanentdata connection to the cellular network. For example, in the LTE (LongTerm Evolution) technology as specified by 3GPP (3^(rd) GenerationPartnership Project), a UE may move between different base stations,referred to as eNB (evolved Node B), and may transition between statesreferred to as “ACTIVE” (or “ECM-CONNECTED”), in which the dataconnection is maintained, and “IDLE” (or ECM-IDLE), in which the dataconnection is released. If the UE has issued an ICN request for acontent object and moved to another access node and/or entered the IDLEmode, the existing ICN/CCN mechanisms might not be sufficient to deliverthe content object to the UE when it becomes available.

Accordingly, there is a need for techniques which allow for efficientutilization of ICN mechanisms in a cellular network.

SUMMARY

According to an embodiment of the invention, a method of conveying datain a cellular network is provided. According to the method, an accessnode of the cellular network determines a correlation of an identifierof a UE with an entry of a Pending Interest Table (PIT) maintained by anICN node. The PIT comprises an entry for each data object having apending ICN request at the ICN node. Based on the correlation, theaccess node controls a connection of the UE with the cellular network.This may involve deciding whether to release the UE to idle mode orpaging of the UE.

According to a further embodiment of the invention, a method ofconveying data in a cellular network is provided. According to themethod, an ICN node maintains a PIT. The PIT comprises an entry for eachdata object having a pending ICN request at the ICN node. The ICN nodereceives, from a UE connected to the cellular network, an ICN requestfor a data object. The ICN node maintains a correlation of an identifierof the UE with that entry of the PIT which corresponds to the requesteddata object.

According to a further embodiment of the invention, a method ofconveying data in a cellular network is provided. According to themethod, a UE sends an ICN request for a data object to an ICN node.Further, the UE receives a paging message from the cellular network. Thepaging message indicates that paging of the UE is due to the ICNrequest.

According to a further embodiment of the invention, an access node for acellular network is provided. The access node is configured to determinea correlation of an identifier of a UE with an entry of a PIT maintainedby an ICN node. The PIT comprises an entry for each data object having apending ICN request at the ICN node. Further, the access node isconfigured to control a connection of the UE with the cellular networkbased on the correlation.

According to a further embodiment of the invention, an ICN node isprovided. The ICN node is configured to maintain a PIT. The PITcomprises an entry for each data object having a pending ICN request atthe ICN node. Further, the ICN node is configured to receive, from a UEconnected to the cellular network, an ICN request for a data object.Further, the ICN node is configured to maintain a correlation of anidentifier of the UE with that entry of the PIT which corresponds to therequested data object.

According to a further embodiment of the invention, a UE is provided.The UE is configured to send an ICN request for a data object to an ICNnode. Further, the UE is configured to receive a paging message from thecellular network. The paging message indicates that paging of the UE isdue to the ICN request.

According to a further embodiment of the invention a system is provided.The system comprises at least one access node according to the aboveembodiment and at least one ICN node according to the above embodiment.Further, the system may comprise at least one UE according to the aboveembodiment.

According to a further embodiment of the invention, a computer programor computer program product is provided, e.g., in the form of anon-transitory storage medium, which comprises program code to beexecuted by at least one processor of an access node for a cellularnetwork. Execution of the program code causes the access node todetermine a correlation of an identifier of a UE with an entry of a PITmaintained by an ICN node. The PIT comprises an entry for each dataobject having a pending ICN request at the ICN node. Further, executionof the program code causes the access node to control a connection ofthe UE with the cellular network based on the correlation.

According to a further embodiment of the invention, a computer programor computer program product is provided, e.g., in the form of anon-transitory storage medium, which comprises program code to beexecuted by at least one processor of an ICN node. Execution of theprogram code causes the ICN node to maintain a PIT. The PIT comprises anentry for each data object having a pending ICN request at the ICN node.Further, execution of the program code causes the ICN node to receive,from a UE connected to the cellular network, an ICN request for a dataobject. Further, execution of the program code causes the ICN node tomaintain a correlation of an identifier of the UE with that entry of thePIT which corresponds to the requested data object.

According to a further embodiment of the invention, a computer programor computer program product is provided, e.g., in the form of anon-transitory storage medium, which comprises program code to beexecuted by at least one processor of a UE. Execution of the programcode causes the UE to send an ICN request for a data object to an ICNnode.

Further, the UE is configured to receive a paging message from thecellular network. The paging message indicates that paging of the UE isdue to the ICN request.

Details of such embodiments and further embodiments will be apparentfrom the following detailed description of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an ICN node as used in an embodiment ofthe invention.

FIG. 2 shows an example of an ICN architecture according to anembodiment of the invention.

FIG. 3A-3E schematically illustrates various ICN networking scenariosaccording to embodiments of the invention.

FIG. 4 shows an example of an LTE cellular network architecture as usedaccording to an embodiment of the invention.

FIG. 5 shows an example of integrating ICN mechanisms in a cellularnetwork according to an embodiment of the invention.

FIG. 6 shows an example of integrating ICN mechanisms with networkarchitecture elements of the LTE technology according to an embodimentof the invention.

FIG. 7 shows an example of a protocol stack which may be used accordingto an embodiment of the invention.

FIG. 8 shows exemplary processes according to an embodiment of theinvention, which involve control of releasing of a UE to idle mode.

FIG. 9 shows further exemplary processes according to an embodiment ofthe invention, which involve control of releasing of a UE to idle mode.

FIG. 10 shows a flowchart for schematically illustrating a methodperformed by an access node according to an embodiment of the invention.

FIG. 11 shows a block diagram for illustrating functionalities of anaccess node according to an embodiment of the invention.

FIG. 12 shows a flowchart for schematically illustrating a methodperformed by an ICN node according to an embodiment of the invention.

FIG. 13 shows a block diagram for illustrating functionalities of an ICNnode according to an embodiment of the invention.

FIG. 14 shows a flowchart for schematically illustrating a methodperformed by a UE according to an embodiment of the invention.

FIG. 15 shows a block diagram for illustrating functionalities of a UEaccording to an embodiment of the invention.

FIG. 16 schematically illustrates structures of devices according toembodiments of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following, concepts in accordance with exemplary embodiments ofthe invention will be explained in more detail and with reference to theaccompanying drawings. The illustrated embodiments relate to conveyingof data in a cellular network using ICN mechanisms, by ICN nodes and ICNmessages. For example, the data may be conveyed on the basis of CCNmechanisms as specified in ICNRG Internet-Drafts “CCNx Semantics”,Version 01, January, 2016, and “CCNx Messages in TLV Format”, Version01, January 2016. However, other ICN, CCN or NDN mechanisms could beutilized as well. Accordingly, in the examples as further detailed belownodes will be referred to as ICN/CCN/NDN nodes, and messages will bereferred to as ICN/CCN/NDN messages.

In CCN, as may be utilized in the examples illustrated below, a ContentObject is retrieved by issuing an Interest message to the network. TheInterest message contains the name of the Content Object. Such a messageis routed by the network towards the source/publisher of the ContentObject. CCN Nodes along the path check if they have a cached copy of theobject. If so they will respond to the Interest message with a Datamessage containing the requested Content Object and the Interest messagewill not be propagated any further. The routing is assisted by the namebeing a structured name (similar to domain names, but with richersyntax). Routers maintain a Forwarding Information Base (FIB) withinformation about where to forward which name or name prefix. Therouters along the path of the Interest message keep a record of theInterest messages they have forwarded (where it came from and whatContent Object it was naming) in a Pending Interest Table (PIT). Ifother Interest messages to the same name arrive to the router, it doesnot forward them, but just notes them in the PIT besides the entry forthis name. This process is called Interest aggregation. As a result, thePIT entries for the same name may form a tree in the network withreceivers as leafs. FIG. 1 shows an overview illustration of a CCN node100 as presented in the keynote of the CCNx Conference 2013, September5th & 6^(th), PARC, Palo Alto, Calif., available on the Internet under“http://security.riit.tsinghua.edu.cn/mediawiki/images/5/53/CCNx-Keynote_Edens.pdf”.As illustrated, the CCN node 100 provides an FIB 110 which storesinformation about which interface (e.g. one of the interfaces)designated by “1”, “2”, and “3”, should be used to find a content objectof a given name. Further, the CCN node 100 provides a PIT 120 whichstores information about what interests are pending. Further, the CCNnode 100 provides a Content Store (CS) 130 which may buffer, i.e.,temporarily store, content objects for potential reuse. ICN/CCN nodes asmentioned below may provide corresponding structures or functionalities.

FIG. 2 schematically illustrates an exemplary CCN scenario.Specifically, FIG. 2 shows a network 200 with network elements 201, 202,203, 204, 205, 206, 207 corresponding to CCN nodes, an end-device 210coupled to the network 200, and a content source 220 coupled to thenetwork 200. The CCN nodes 201, 202, 203, 204, 205, 206, 207 maycorrespond to routers. The end-device 210 may correspond to a userterminal, such as a UE with cellular network connectivity. The contentsource 220 may correspond to a server.

FIG. 3A to 3E are based on the scenario of FIG. 2 and illustrate variousaspects of ICN/CCN including prefix routing, caching at ICN/CCN nodes,i.e., temporary storage of a Content Object in the CS, and optimizeddelivery of cached Content Objects. Specifically, FIG. 3A shows that theend-device 210 sends an Interest message (illustrated by the arrow) torequest a Content Object which is available from the content source 220.The Interest message identifies the Content Object by a name.

As a next step, FIG. 3B illustrates prefix routing to determine a routethrough the network 200 to the requested Content Object. The prefixrouting utilizes a part of the name of the content object, referred toas prefix, and matching of the prefix to entries of the FIB of the CCNnodes 201, 202, 203, 204, 205, 206, 207. As indicated by the arrows inFIG. 3B, a route from the end-device 210 to the content source 220,extending via the CCN nodes 201, 202, 203, 204, is obtained in this way.At each of these CCN nodes, it is checked whether the Content Object islocally available in the CS, and if this is not the case, the Interestis forwarded to the next-hop CCN node, and a corresponding entry isstored in the PIT. In the illustrated scenario, it is assumed that theContent Object is available only at the content source 220 and theInterest is thus propagated up to the content source to 220. As a nextstep, FIG. 3C illustrates caching of the Content Object at the CCN nodesalong the determined route. In particular, the Content Object isprovided in Data messages from the content source 220 via the CCN nodes204, 203, 202, 201 to the end-device 210, as illustrated by the solidarrows, and the content object is cached by each of the CCN nodes 204,203, 202, 201.

As illustrated by FIG. 3D, the caching of the Content Object may beutilized for optimized content delivery. In the example of FIG. 3D,another end-device 211 requests the same Content Object by sending anInterest message naming this Content Object (illustrated by an openarrow) to the CCN node 201. Because the content object is cached at theCCN node 201, the CCN node 201 can directly respond to the end-device211 with a data message including the requested Content Object(illustrated by a solid arrow), without further propagating theInterest.

As illustrated by FIG. 3E, also mobility of the end-device may behandled in an efficient manner. In the example of FIG. 3E, it is assumedthat the end device 211 moved and is now connected to the CCN node 205before the requested Content Object was delivered to the end device 211.This is addressed by the end-device 211 resending the Invite message,thereby informing the ICN network 200 that the end-device 211 moved andinitiating updating of the FIBs and PITs. In the illustrated example, aroute to the content object, which is cached at the CCN node 203 isdetermined by prefix routing, as indicated by open arrows, and thecontent object can then be delivered from the CCN node 203 via the CCNnode 205 to the end device 211, as indicated by solid arrows.

Accordingly, when the Interest message reaches an endpoint (or router)having a copy of the Content Object (perhaps cached), the Interestmessage is responded to with a Data message, which is propagatedbackwards along the path the Interest message took. The backward path islearned from the entries the Interest message left in the PIT of therouters along the path. If there were multiple Interests arriving at arouter for this name, the Data message containing the Content Object isreplicated towards each direction, where the Interest messages camefrom. After forwarding a Content Object matching a pending Interest, therouters delete the corresponding entry in the PIT, thus these entriesare expected to be short-lived. When the original endpoint(s) generatingthe Interest message(s) receive the Content Object the transaction isconsidered closed.

The Interest aggregation mechanism typically forms a hierarchical treein the ICN/CCN network where request packets are aggregated and responsepackets are de-aggregated at each level of the tree. This allows ICNnetworks to scale with increasing number of clients.

FIG. 4 illustrates architecture elements of a cellular network based onthe LTE technology as defined in 3GPP TS 36.300 V13.2.0 (2015-12). Asillustrated, in this case the cellular network includes radio accessnodes in the form for eNBs and HeNBs (HeNB: Home eNB). The eNBs andHeNBs are connected by interfaces referred to as “X2”. Furtherarchitecture elements include an X2 Gateway (X2 GW), an HeNB Gateway(HeNB GW), and MME/S-GWs. As illustrated, the X2 GW may serve as onoptional intermediate node of the X2 interface between two or more ofthe eNBs and HeNBs. The MME/S-GWs and the HeNB GW serve as control nodesand data plane gateways for the eNBs and HeNBs and are connected theretovia interfaces referred to as “S1”. As further illustrated, an HeNB mayalso be connected to an MME/S-GW via an interface referred to as “S5”.The eNBs and HeNBs (as well as the X2 GW and the HeNB GW) are regardedas elements of the Evolved UMTS Terrestrial Radio Access Network(E-UTRAN), and the MME/S-GWs are regarded as elements of the EvolvedPacket Core (EPC) of the Evolved Packet System (EPS).

The EPS includes the E-UTRAN the EPC and LTE capable UEs. Two differentconnection management states are defined in which the UE can be, whichare referred to as ECM-IDLE (or “IDLE”) and ECM-CONNECTED (or “ACTIVE).In ECM-IDLE, the UE position is known on Tracking Area (TA) level. SuchTAs can consist of one or more cells. The UE does not have any activeRRC (Radio Resource Control) or S1 connection. To reach the UE, the MMEin the EPC will initiate paging by sending paging messages over S1 tothe eNBs in the TA(s) that the UE is located in. The eNBs will then pagethe UE over the LTE radio interface (referred to as Uu interface). InECM-CONNECTED, the UE position is known on cell level in the E-UTRAN andthere is an active RRC and S1 connection. This state is used for datatransmission to and from the UE, and when the UE moves the UE will behanded over to other cells. Inactive UEs are typically released toECM-IDLE state in order to reduce UE battery consumption and to minimizesignalling in the network.

One possibility for introducing ICN/CCN enhancements in a cellularnetwork is to introduce ICN/CCN router functionality in the cellularbase station (or in the vicinity of the cellular base station), e.g., inor in the vicinity of the eNBs or HeNBs as shown in FIG. 4. In this casethe base station can provide connectivity for the cellular userequipment (UEs) to the nearest ICN/CCN router. Such a case isillustrated below when CCN router functionality is included in an LTEeNB. In such cases it is still likely that the cellular network (e.g.MMEs, eNBs) would still control mobility events such as handovers andstate transitions, e.g., between ECM-CONNECTED and ECM-IDLE and viceversa.

One particular problem that could occur in this type of ICN/CCN solutionis that the UE could have issued an Interest message for a ContentObject, but not yet have received the Content Object, i.e., have apending ICN request in the ICN/CCN network, but is otherwise inactive inthe cellular network and is therefore released to ECM-IDLE state. Inthis case, when the Content Object arrives at the eNB which recentlyserved the UE, there is no way for the eNB to deliver the Content Objectto the UE, since the UE is no longer reachable on cell level.

In the concepts as illustrated herein, the above-mentioned problem andsimilar problems, e.g., arising from mobility of the UE while inECM-IDLE, are addressed by using a correlation of an identifier of theUE to the pending ICN request. Based on this correlation, an accessnode, such as an ENB, can control connection of the UE to the cellularnetwork. For example, if the correlation indicates that there is nopending ICN request and the UE is otherwise inactive, the access nodemay release the connection of the UE to the cellular network, e.g., byinitiating a transition of the UE to the ECM-IDLE state. Further, if thecorrelation indicate that there is a pending ICN request, the accessnode may prevent releasing the connection, e.g., by keeping the UE inthe ECM-CONNECTED state.

Accordingly, embodiments as described herein relate to a communicationscenario between an eNB in an LTE-RAN, and in ICN/CCN node in an ICN/CCNnetwork. A UE is in the coverage area of the eNB. The UE has anidentifier applicable to making a request for content via the ICN/CCNnetwork. The UE identifier can be embodied or can comprise an UE(context) identity or any other identity in relation to making therequest. ICN information, such as the PIT of the ICN node, is correlatedwith the identifier of the UE. This correlation can be also called anassociation or a connection or linking.

One embodiment is to avoid releasing inactive UEs with an active requestin the PIT. The eNB would in this case check the PIT for any pendingrequest for a specific UE when the inactivity timer times out for thatUE. If there is no entries in the PIT the eNB will release the UE toECM-IDLE (which may be done by sending RRC connection release message).If there is a pending ICN request, the eNB will not release the UE. Inthe latter case the eNB could for instance start another timer whichgoverns how long the eNB should wait for the pending interest to go awaybefore releasing the UE.

Another embodiment involves that if the eNB has released a UE toECM-IDLE with a pending ICN request in the PIT, the eNB or an ICN nodewould remember the UE identity associated with the pending request andinitiate paging for the UE when the data object associated with thatpending request arrives. Paging of the UE involves that one or more eNBssend a paging message to the UE. The paging message can either be sentdirectly by the eNB in the cell the UE was connected to or a trigger canbe sent to the MME to initiate paging. In case the UE returns to thesame ICN node it should be possible to deliver the data object to the UEeither directly because the ICN node knows it is the same UE, or by theUE re-requesting the object which the ICN node now has in its cache. Theidentity used for associating the pending request can be a S-TMSI of theUE, a S5 GTP identity of the UE, or a C-RNTI of the UE used in EPS.However, any other identity could be used as well.

The illustrated embodiments allow to make sure that the data object thatthe UE has requested will be delivered when it arrives. It can beavoided that the UE needs to re-request the object based on some timer,which could add unnecessary signaling or delays.

In the following, several aspects of the present disclosure will bediscussed. These aspects are based on the overall assumption that anICN/CCN network is integrated into a cellular network. An example ofintegrating the ICN/CCN network with a cellular network is shown in FIG.5. As illustrated in FIG. 5, an ICN/CCN/NDN cloud 500 includes ICN nodes501, 502, 503, 504, 505. The ICN/CCN/NDN cloud 500 is connected to an IPbased part of the Internet, referred to as IP Internet 510, and to anICN/CCN/NDN based part of the Internet, referred to as ICN/CCN/NDNInternet 520. Access nodes 531, 532 are connected to the ICN/CCN/NDNcloud 500, and a UE 510 may access the IP Internet 510 and/or theICN/CCN/NDN Internet 520 via these access nodes 531, 532, and movebetween these access nodes 531, 532. As further illustrated, theICN/CCN/NDN cloud 500 may also be connected to servers 540, which mayfor example store content and/or provide services.

FIG. 6 further illustrates a how the ICN/CCN network may be integratedwith elements of a cellular network based on the LTE technology. Asillustrated in FIG. 6, an eNB 620 provides access a UE 610 with accessto the cellular network. Through an ICN/CCN node 670, the UE 610 mayaccess an ICN/CCN data network 680. As illustrated, this access may beimplemented directly at the eNB 620. For example, the ICN/CCN node couldbe co-located with the eNB 620 or integrated in the eNB 620. Further,the UE 610 may access an “Internet” data network 660 through an S-GW630, and a P-GW (Packet Data Network Gateway) 640, controlled by an MME650, i.e., through the EPC. Accordingly, ICN/CCN traffic does not needto pass though the S-GW 630 and PGW 640. Mobility for the ICN/CCNtraffic may be handled by the ICN/CCN network while radio handovers toor from other eNBs may be handled by the eNB 620 and the MME 650.

FIG. 7 illustrates an example of a data plane protocol stack which maybe utilized in a scenario as illustrated in FIG. 6. As can be seen, aCCN/NDN protocol layer may be arranged between an application levelprotocol layer (APP) and lower protocol layers. On the Uu radiointerface of the LTE technology, these lower protocol layer wouldinclude a PDCP (Packet Data Convergence Protocol) layer, an RLC (RadioLink Control) layer, a MAC (Medium Access Control) layer, and a physicallayer (also referred to as L1). On the other interfaces, i.e., an S1 uinterface between eNB and CCN/NDN router (such as one of the ICN nodes501, 502, 503), and an S6/S8 interface between CCN/NDN router andCCN/NDN GW/proxy (such as one of the ICN nodes 504, 505), other L1, L2,and/or L3 protocols may be used, depending on the implementation ofthese interfaces. Between CCN/NDN GW/proxy and a server or content owner(such as one of the servers 640 or a content source accessible throughthe IP Internet 510), the ICN/CCN traffic may be conveyed over the SGiinterface, without using ICN/CCN/NDN protocol enhancements.

As mentioned above, the ICN nodes (such as the ICN/CCN node 670 of FIG.6) maintain a PIT with entries for each pending ICN request for a dataobject. In the case of CCN, such pending ICN request would be a pendingInterest for a Content Object. For efficiently supporting mobility ofUEs and various connection states of UEs, such as ECM-IDLE andECM-CONNECTED, a UE context identifier may be linked with the pendingICN request in the PIT.

Accordingly, whenever the ICN functionality in the ICN node integratedin the cellular network receives a request for a data object that itdoes not have stored in its cache, it will add the ICN request to thePIT. Typically, in a normal ICN operation it would be enough toassociate this ICN request with the interface over which the request wasreceived so that the ICN node can send the requested data object backover the same link. In the concepts as illustrated herein, with ICNnetwork being integrated in the cellular network, the ICN request isfurther associated with a UE context, so that the eNB (or similar accessnode) can deliver the data object to the right UE. According to theillustrated concepts, this UE context association may be used to alsolink the information in the PIT with the UE state or context identifiersused for paging the UE in ECM-IDLE. The associated UE context identifiercould be the S-TMSI (Temporary Mobile Subscriber Identity for S typeinterface), the GUTI (Global Unique Temporary Identity) or the IPaddress of the UE, or the MME UE S1AP ID (S1 Application ProtocolIdentifier) or eNB UE S1AP ID used as identifier over S1, or the C-RNTI(Cell Radio Network Temporary Identity) used for scheduling over theradio interface, or a new identifier used specifically for ICN/CCN, oran S5 GTP (S5 GPRS Tunneling Protocol) identity, e.g., S5 GTP TEID (S5GTP Tunnel Endpoint Identifier), assuming there is an S5 interfacebetween eNB and S-GW, or any other identifier. This identifier could bestored in the PIT for each UE request.

Accordingly, the eNB may store a UE identity when the UE is released toECM-IDLE and also when the UE is in ECM-CONNECTED. For some kind of UEidentifier, such as S-TMSI or GUTI, this requires that the identifier isprovided to the eNB, e.g., from the MME (using S1 signaling) or fromother eNBs (using X2 signaling) in case of handover for all UEs usingICN/CCN.

In some aspects, the illustrated concepts may be used to avoid releasinga UE to ECM-IDLE if it has a pending ICN request. As mentioned above,one embodiment of the present disclosure is to avoid releasing inactiveUEs with an active request in the PIT. The eNB would in this case checkthe PIT for any pending request for a specific UE when the inactivitytimer times out for that UE. The inactivity timer in this case could bea common timer used by the eNB to release any UEs to ECM-IDLE when theyhave not had any traffic for a while. Given that the ICN network mightneed to retrieve the content from several hops away it could havehappened that this timer has timed out before the data object reachesthe eNB. This checking may be based on the UE context identity beingstored in the PIT, as further explained below.

If there are no entries in the PIT which are associated with the UEcontext identifier, the eNB may release the UE to ECM-IDLE. This may bedone by the eNB requesting the MME to release the UE, which results inthat the S1 connection of the UE is released and the eNB sends a RRCconnection release message to the UE to release the RRC connection.

If there is one or more pending request the eNB will not release the UE.In this case the eNB can wait and re-evaluate the need to release UEonce the data object(s) associated with the pending request(s) has/havebeen delivered (i.e. when the pending request has been removed). In somescenarios, it is also possible for the eNB to start a timer associatedwith the pending request(s), and if the pending request(s) is/are stillthere (i.e. the request has not been fulfilled) when the associatedtimer has timed out, the eNB can release the UE to ECM-IDLE stateanyway. The latter solution can be used to avoid that UEs are kept toolong in ECM-CONNECTED.

FIG. 8 illustrates exemplary processes which may be used forimplementing the above control of releasing of a UE to ECM-IDLE. Theprocesses of FIG. 8 involve the UE 610, the eNB 620, and the ICN/CCNnode 670.

As illustrated by message 802, the UE 610 may send an ICN request for adata object (e.g., certain content) to the eNB 620. The eNB 620 may thenforward the ICN request together with a UE identifier to the ICN/CCNnode 670. As mentioned above, the UE identifier may include an S-TMSI, aGUTI, an IP address, an MME UE S1AP ID, an eNB UE S1AP ID, a C-RNTI, oran S5 GTP TEID, or the like. If needed, the eNB 620 may obtain theidentifier from another node, e.g., from the MME 650.

In the illustrated example, it is assumed that the requested data objectis not cached at the ICN/CCN node 670, and the ICN/CCN request is thuspropagated by the ICN/CCN node 670 to the ICN/CCN data network. Asillustrated by step 803, the ICN/CCN node 670 further enters the requestin the PIT maintained by the ICN/CCN node 670.

As further illustrated by step 804, the ICN/CCN node stores acorrelation of the UE identifier and the request. For example, this maybe accomplished by storing the UE identifier in an entry of the PITwhich corresponds to the request. In some scenarios, when multiple UEshave requested the same data object, the PIT entry corresponding to therequest may include multiple UE identifiers.

As illustrated by step 805, at some time the eNB 620 may then need todecide whether to release the UE 610 to ECM-IDLE. For example, the UE610 may have been inactive for some time, which may be detected based onexpiry of an inactivity timer. To save battery and signaling resources,it may thus be desirable to release the UE 610 to ECM-IDLE. However, thedecision whether to release the UE 610 to ECM-IDLE is also based onwhether there is a pending ICN request of the UE.

Accordingly, the eNB 620 interrogates with the ICN/CCN node 670 whetherthere is a pending ICN request of the UE 610 in the PIT, as illustratedby signaling 806. The interrogation is based on the UE identifier andthe stored correlation of the UE identifier to the request in the PIT.

If the correlation indicates that there is no request from the UE 610 inthe PIT (e.g., because the requested data object was already deliveredto the UE 610), the eNB 620 may release the UE 610 to ECM-IDLE bysending an IDLE mode command 807 to the UE 610. For example, the eNB 620may request the MME 650 to release the UE 610, and the IDLE mode command807 may then correspond to an RRC connection release message.Alternatively, if the correlation indicates that there is no requestfrom the UE 610 in the PIT, the eNB 620 may leave the UE 610 in theECM-CONNECTED state, as indicated by step 808.

FIG. 9 illustrates further exemplary processes which may be used forimplementing the above control of releasing of a UE to ECM-IDLE. Theprocesses of FIG. 9 involve the UE 610, the eNB 620, and the ICN/CCNnode 670.

As illustrated by message 902, the UE 610 may send an ICN request for adata object (e.g., certain content) to the eNB 620. The eNB 620 may thenforward the ICN request to the ICN/CCN node 670.

As further illustrated by step 903, the eNB 620 stores a correlation ofa UE identifier and the request. For example, the eNB 620 may store aname of the data object together with the UE identifier as an indicationthat there is a pending request for the data object in the PIT of theICN/CCN node 670. When the data object is delivered to the UE 610, thisindication may be deleted. As mentioned above, the UE identifier mayinclude an S-TMSI, a GUTI, an IP address, an MME UE S1AP ID, an eNB UES1AP ID, a C-RNTI, or an S5 GTP TEID, or the like. If needed, the eNB620 may obtain the identifier from another node, e.g., from the MME 650.

In the illustrated example, it is assumed that the requested data objectis not cached at the ICN/CCN node 670, and the ICN/CCN request is thuspropagated by the ICN/CCN node 670 to the ICN/CCN data network. Asillustrated by step 904, the ICN/CCN node 670 further enters the requestin the PIT maintained by the ICN/CCN node 670.

As illustrated by step 905, at some time the eNB 620 may then need todecide whether to release the UE 610 to ECM-IDLE. For example, the UE610 may have been inactive for some time, which may be detected based onexpiry of an inactivity timer. To save battery and signaling resources,it may thus be desirable to release the UE 610 to ECM-IDLE. However, thedecision whether to release the UE 610 to ECM-IDLE is also based onwhether there is a pending ICN request of the UE. In the processes ofFIG. 9, the eNB 620 may use the locally stored correlation of the UEidentifier to pending request(s) to determine whether there is a pendingICN request of the UE 610 in the PIT.

If the correlation indicates that there is no request from the UE 610 inthe PIT (e.g., because the requested data object was already deliveredto the UE 610), the eNB 620 may release the UE 610 to ECM-IDLE bysending an IDLE mode command 906 to the UE 610. For example, the eNB 620may request the MME 650 to release the UE 610, and the IDLE mode command807 may then correspond to an RRC connection release message.Alternatively, if the correlation indicates that there is no requestfrom the UE 610 in the PIT, the eNB 620 may leave the UE 610 in theECM-CONNECTED state, as indicated by step 907.

It is noted that in some scenarios the UE 610 could also be released toECM-IDLE if the correlation indicates that there is a pending ICNrequest from the UE 610. For example, such release could be triggered byexpiry of a further timer, configured with a longer duration than theinactivity timer.

In some aspects, the illustrated concepts may also be used to handlecases when a requested the data object arrives for a UE that has alreadybeen released to ECM-IDLE: In cases where a UE with a pending request inthe PIT has been released to ECM-IDLE, the eNB and/or ICN node canremember the UE identity associated with the pending request, i.e.,maintain a correlation of the UE identity the request in the PIT, andinitiate paging of the UE when the data object associated with thatpending request arrives. In the following, various options ofimplementing this paging will be described.

According to a first option, the eNB may page the UE directly, e.g.,using the S-TMSI of the UE in the local coverage area of the eNB. Inother words, the eNB itself may send a paging message to the UE. Whenthe UE receives the paging message (assuming it is still in the localarea) the UE will typically contact the network by sending a NAS (NonAccess Stratum) service request. This NAS service request will in turntrigger the setup of the RRC and S1 connection as well as user planeradio bearers for the UE, and the UE will enter the ECM-CONNECTED state.Once the user plane radio bearers are setup, the data object can bedelivered to the UE by the eNB and/or ICN node. If the UE has moved tooutside the local area of the eNB, the eNB will not receive a responseto the paging message and can then optionally trigger paging accordingby one or more other eNBs, e.g., according to the second option asexplained below. In the latter case, the eNB may have stored paginginformation for the UE, such as the paging identity to use, possiblepaging group the UE belongs to (or paging offset) and/or a DRX(Discontinuous Reception) period configured for the UE.

According to a second option, the eNB or ICN node may trigger paging ofthe UE by sending a message over S1 (or S11 interface) to the MMEassociated with the UE context (this can be determined by the UE S-TMSIor GUTI). The message indicates to the MME that the UE shall be paged.The MME may then initiate paging according to normal UE pagingprocedures. When the UE receives the page it will respond with a NASservice request which will trigger the setup of the RRC and S1connection as well as user plane radio bearers, and the UE will enterthe ECM-CONNECTED state. If the UE returns to an ICN node which alsoserved the same areas as the UE was in before entering ECM-IDLE, thisICN node can also deliver the data object to the UE. If the eNB or ICNnode also triggered the paging because the data object became availableat the eNB/ICN node, the delivery of the data object can be done withoutUE re-requesting the object. If the UE connects to a different ICN node,the UE can re-request the data object. In the latter case, it is likelythat the delivery of the data object to the new ICN node will be fastand long before the UE might time out to ECM-IDLE again, because thedata object has already been delivered to an eNB or ICN node in thevicinity. In order to trigger the UE to re-request the data object, thenetwork can send a message to the UE over the radio interface that theUE has entered a new ICN node so that any pending requests should bere-sent. This message can also include an identifier of the ICN node(e.g., an ICN node ID) which would make it possible for the UE todetermine this information by itself.

According to a third option, it is assumed that there was an S5interface configured between the S-GW serving the UE and the localeNB/ICN node to which the UE issued the ICN request. In this case thelocal eNB/ICN node can send a DL (Downlink) packet to the S-GW totrigger the S-GW to initiate paging by sending a Data Notificationmessage to the MME. The DL packet could either be a dummy packet, orsome ICN signaling, or the requested data object. An advantage of thelatter option is that the ICN data object can be delivered to the UEeven if the UE shows up (answers the page) at a different eNB/ICN nodesince the data can be delivered via the S-GW to that eNB/ICN node.

In addition to the above options it is also possible to add additionalinformation in the page request sent to the UE based on ICN knowledge inthe network. Possible information includes, without limitation, a flagindicating that the page is triggered from the ICN network, informationabout the data object that was received at the ICN node or eNB, e.g.,the name of the data object, or a hash or checksum of the data objectname. Using the hash or checksum may allow for reducing the size of thepaging message. Including additional information with the paging mayenable the UE or ICN application in the UE to decide if it wants toenter ECM-CONNECTED to receive the content or not. If for instance theUE has already determined it is no longer interested in the date object,it could ignore the page. Further, Including additional information withthe paging may be used a trigger for the UE to re-send an ICN request orto register to the ICN network after it has responded to the page.

In addition to the above options it is also possible to utilize aspecial paging resource for ICN related paging. In this case all UEswhich have pending ICN requests and that are sent to ECM-IDLE couldmonitor the ICN paging channel to see when there is ICN data for them.An advantage of this option could be that the eNB would not need to knowthe normal paging slots that the UE uses since the UE can be reached onthe ICN paging channel/slots. It would also make it possible to applydifferent DRX periods for ICN and non-ICN data which would affect UEbattery consumption and latency. By way of example, ICN paging slotscould be more frequent to reduce the delay at the expense of more UEbattery consumption if the UE has a pending ICN request.

FIG. 10 shows a flowchart for illustrating a method of conveying data ina cellular network. The method of FIG. 10 may be utilized forimplementing the illustrated concepts in an access node of the cellularnetwork, such as one of the access nodes 531, 532, or the eNB 620. If aprocessor-based implementation of the access node is used, the steps ofthe method may be performed by one or more processors of the accessnode. In such a case the access node may further comprise a memory inwhich program code for implementing the below described functionalitiesis stored.

At optional step 1010, the access node may receive an ICN request for adata object from a UE. In accordance with ICN principles, the ICNrequest identifies the data object by a name and is not addressed to aspecific source of the data object. The ICN request may for example bean Interest message according to the CCNx specifications.

At optional step 1020, the access node may forward the ICN request to anICN node. In accordance with ICN principles, the ICN node will maintaina PIT which includes an entry for each data object having a pending ICNrequest at the ICN node.

At optional step 1030, the access node may maintain a correlation of anidentity of the UE with the entry of the PIT corresponding to the ICNrequest. The identity may include an S-TMSI, a GUTI, an IP address, anMME UE S1AP ID, an eNB UE S1AP ID, a C-RNTI, or an S5 GTP TEID.Maintaining the correlation may involve storing the identity of the UEat the access node, e.g., in a table, database, or the like. Theidentity may be stored in association with the ICN request, e.g., bylinking it to the name of the requested data object. An example ofcorresponding processes is explained in connection with FIG. 9. Inaddition or as an alternative, maintaining of the correlation mayinvolve indicating the identity of the UE to the ICN node, so that acorrelation of the identity of the UE with the entry of the PIT can bemaintained at the ICN node. An example of corresponding processes isexplained in connection with FIG. 8.

At step 1040, the access node determines a correlation of an identifierof a UE, such as one of the UEs 210, 211, 510, 610 with an entry of aPIT maintained by an ICN node, such as one of the ICN nodes 201, 202,203, 204, 205, 206, 207; 501, 502, 503, 504, 505, 670. The PIT includesan entry for each data object having a pending ICN request at the ICNnode. The ICN request may correspond to the ICN request received at step1010 and forwarded at step 1020. The correlation may correspond to thecorrelation as maintained at step 1030.

In some scenarios, step 1040 may involve that, based on the identity ofthe UE, the access node interrogates with the ICN node to determinewhether an ICN request from the UE is pending at the ICN node. Anexample of corresponding processes is explained in connection with FIG.8.

At step 1050, the access node controls a connection of the UE with thecellular network. This may involve that, in response to the correlationindicating that no ICN request from the UE is pending at the ICN node,the access node initiates releasing of the connection to the UE. Here,it is noted that other criteria for releasing the connection may existas well, such as expiry of an inactivity timer. Further, step 1050 mayinvolve that, based on the correlation indicating that a data objecthaving a pending ICN request from the UE has become available at the ICNnode, the access node initiates paging of the UE. For example, in thiscase the correlation may enable the access node to determine informationrequired for paging the UE.

Paging of the UE may include sending a paging message to the UE. Thepaging message may indicate that the paging of the UE is due to apending ICN request, e.g., in terms of a flag. In some scenarios, thepaging message may also include information on the available dataobject, e.g., a name of the data object or a hash of the name of thedata object. In some scenarios, the paging message may also include anindication for triggering re-sending of the ICN request.

FIG. 11 shows a block diagram for illustrating functionalities of anaccess node 1100 which operates according to the method of FIG. 10. Asillustrated, the access node 1100 may optionally be provided with amodule 1110 configured to receive an ICN request from a UE, such asexplained in connection with step 1010. Further, the access node 1100may optionally be provided with a module 1120 configured to forward theICN request to an ICN node, such as explained in connection with step1020. Further, the access node 1100 may optionally be provided with amodule 1130 configured to maintain a correlation of an identity of theUE with an entry of the PIT corresponding to the ICN request, such asexplained in connection with step 1030. Further, the access node 1100may be provided with a module 1040 configured to determine a correlationof an identity of a UE with an entry of a PIT, such as explained inconnection with step 1040. Further, the access node 1100 may be providedwith a module 1150 configured to control connection of the UE to thecellular network, such as explained in connection with step 1050.

It is noted that the access node 1100 may include further modules forimplementing other functionalities, such as known functionalities of aneNB. Further, it is noted that the modules of the access node 1100 donot necessarily represent a hardware structure of the access node 1100,but may also correspond to functional elements, e.g., implemented byhardware, software, or a combination thereof.

FIG. 12 shows a flowchart for illustrating a method of conveying data ina cellular network. The method of FIG. 12 may be utilized forimplementing the illustrated concepts in an ICN node, such as one of theICN nodes 201, 202, 203, 204, 205, 206, 207; 501, 502, 503, 504, 505;670. If a processor-based implementation of the ICN node is used, thesteps of the method may be performed by one or more processors of theICN node. In such a case the ICN node may further comprise a memory inwhich program code for implementing the below described functionalitiesis stored.

At step 1210, the ICN node maintains PIT. The PIT includes an entry foreach data object having a pending ICN request at the ICN node.

At step 1220, the ICN node receives an ICN request for a data object. Inaccordance with ICN principles, the ICN request identifies the dataobject by a name and is not addressed to a specific source of the dataobject. The ICN request may for example be an Interest message accordingto the CCNx specifications. The ICN request is received from a UEconnected to the cellular network, such as one of the UEs 210, 211, 50,610. It is noted that the request may be received via one or moreintermediate nodes, e.g., via an access node, such as one of the accessnodes 531, 532, or the eNB 620, or even via a further ICN node. At step1230, the ICN node maintains a correlation of an identifier of the UEwith that entry of the PIT which corresponds to the requested dataobject. The identity may include an S-TMSI, a GUTI, an IP address, anMME UE S1AP ID, an eNB UE S1AP ID, a C-RNTI, or an S5 GTP TEID.Maintaining the correlation may involve storing the identity of the UEin the entry of the PIT. In addition or as an alternative, maintainingof the correlation may involve receiving the identity of the UE from anaccess node of the cellular network, such as one of the access nodes531, 532, or the eNB 620. An example of corresponding processes isexplained in connection with FIG. 8.

At optional step 1240, based on the correlation indicating that a dataobject having a pending ICN request from the UE has become available atthe ICN node, the ICN node may initiate paging of the UE. Typically,paging may be initiated when the UE is in idle mode, i.e., does not havea data connection to the cellular network, such as when the UE is in theECM-IDLE state.

Paging of the UE may include sending a paging message to the UE. Thepaging message may indicate that the paging of the UE is due to apending ICN request, e.g., in terms of a flag. In some scenarios, thepaging message may also include information on the available dataobject, e.g., a name of the data object or a hash of the name of thedata object. In some scenarios, the paging message may also include anindication for triggering re-sending of the ICN request.

In some scenarios, the ICN node may interrogate with an access node ofthe cellular network to determine whether an ICN request from the UE ispending at the ICN node. The access node has a coverage area in whichthe UE is located. An example of corresponding processes is explained inconnection with FIG. 8.

FIG. 13 shows a block diagram for illustrating functionalities of an ICNnode 1300 which operates according to the method of FIG. 12. Asillustrated, the ICN node 1300 may be provided with a module 1310configured to maintain a PIT, such as explained in connection with step1210. Further, the ICN node 1300 may be provided with a module 1320configured to receive an ICN request from a UE, such as explained inconnection with step 1220.

Further, the ICN node 1300 may be provided with a module 1330 configuredto maintain a correlation of an identity of the UE with an entry of thePIT corresponding to the ICN request, such as explained in connectionwith step 1230. Further, the ICN node 1300 may optionally be providedwith a module 1340 configured to initiate paging based on the maintainedcorrelation, such as explained in connection with step 1240.

It is noted that the ICN node 1300 may include further modules forimplementing other functionalities, such as known functionalities of anICN/CCN/NDN node. Further, it is noted that the modules of the ICN node1300 do not necessarily represent a hardware structure of the ICN node1300, but may also correspond to functional elements, e.g., implementedby hardware, software, or a combination thereof.

FIG. 14 shows a flowchart for illustrating a method of conveying data ina cellular network. The method of FIG. 14 may be utilized forimplementing the illustrated concepts in a UE, such as one of the UEs210, 211, 510, 610. If a processor-based implementation of the UE isused, the steps of the method may be performed by one or more processorsof the UE. In such a case the UE may further comprise a memory in whichprogram code for implementing the below described functionalities isstored.

At step 1410, the UE sends sending an ICN request for a data object toan ICN node, such as one of the ICN nodes 201, 202, 203, 204, 205, 206,207; 501, 502, 503, 504, 505; 670. In accordance with ICN principles,the ICN request identifies the data object by a name and is notaddressed to a specific source of the data object. The ICN request mayfor example be an Interest message according to the CCNx specifications.

At step 1420, the UE receives a paging message from the cellularnetwork. The UE may receive the paging message while being in idle mode,i.e., while it does not maintain a data connection to the cellularnetwork. For example, after having sent the ICN request at step 1410,the UE may have changed idle mode. The paging message indicates thatpaging of the UE is due to the ICN request. The paging message may alsoindicate that the data object is available at the ICN node. Further, thepaging message may include information on the available data object.Further, the paging message may include an indication for triggeringre-sending of the ICN request by the UE.

At optional step 1430, the UE may control re-sending of the ICN requestbased on the paging message. In some cases, the UE may re-send the ICNrequest, e.g., in situations when the UE has moved to another ICN node.In other cases, the UE may not re-send the ICN request, e.g., insituations when the UE has re-connected to the same ICN node to which itsent the request at step 1410. Further, based on information included inthe paging message, the UE may decide whether to leave an idle mode, inwhich the UE has no data connection to the cellular network. Forexample, the UE may decide whether to leave the ECM-IDLE state and toenter the ECM-CONNECTED state.

FIG. 15 shows a block diagram for illustrating functionalities of a UE1500 which operates according to the method of FIG. 14. As illustrated,the UE 1500 may be provided with a module 1510 configured to send an ICNrequest to an ICN node, such as explained in connection with step 1410.Further, the UE 1500 may be provided with a module 1520 configured toreceive a paging message, such as explained in connection with step1420. Further, the UE 1500 may optionally be provided with a module 1530configured to control re-sending of the ICN request, such as explainedin connection with step 1430.

It is to be understood that the methods of FIGS. 10, 12, and 14 couldalso be combined. For example, the methods FIG. 10 and FIG. 12 could becombined in a system including one or more access nodes operatingaccording to the method of FIG. 10 and one or more ICN nodes operatingaccording to the method of FIG. 12.

FIG. 16 illustrates processor-based implementations of a UE 1610, anaccess node 1620, assumed as an eNB, and an ICN/CCN node 1630, which maybe used in the concepts as explained above.

As illustrated, the UE 1610 includes a radio interface 1611 forconnection to the eNB 1620, one or more processors 1613, and a memory1614. The UE 1610 may correspond to a UE operating according to themethod of FIG. 14, such as one of the above-mentioned UEs 210, 211, 510,610. The interface 1611, the processor(s) 1613, and the memory 1614 maybe coupled by one or more internal bus systems of the UE 1610. Thememory 1614 may include a Read Only Memory (ROM), e.g., a flash ROM, aRandom Access Memory (RAM), e.g., a Dynamic RAM (DRAM) or Static RAM(SRAM), a mass storage, e.g., a hard disk or solid state disk, or thelike. The memory 1614 may include suitably configured program code to beexecuted by the processor(s) 1613 so as to implement the above-describedfunctionalities of a UE, such as explained in connection with FIG. 14.

As further illustrated, the eNB 1620 includes a radio interface 1621 forconnection to the UE 1610, an ICN/CCN interface 1622 for connection tothe ICN/CCN node 1630, one or more processors 1623, and a memory 1624.The eNB 1620 may correspond to an access node operating according to themethod of FIG. 10, such as one of the above-mentioned access node 531,532 or the eNB 620. The interfaces 1621, 1622 the processor(s) 1623, andthe memory 1624 may be coupled by one or more internal bus systems ofthe eNB 1620. The memory 1624 may include a ROM, e.g., a flash ROM, aRAM, e.g., a DRAM or SRAM, a mass storage, e.g., a hard disk or solidstate disk, or the like. The memory 1624 may include suitably configuredprogram code to be executed by the processor(s) 1623 so as to implementthe above-described functionalities of an access node, such as explainedin connection with FIG. 10.

As further illustrated, the ICN/CCN node 1630 includes an eNB interface1632 for connection to the eNB 1620, one or more processors 1633, and amemory 1634. Further, the ICN node 1630 may correspond to an ICN nodeoperating according to the method of FIG. 12, such as one of theabove-mentioned ICN nodes 201, 202, 203, 204, 205, 206, 207; 501, 502,503, 504, 505; 670. The interface 1631, the processor(s) 1633, and thememory 1624 may be coupled by one or more internal bus systems of theICN/CCN node 1630. The memory 1634 may include a ROM, e.g., a flash ROM,a RAM, e.g., a DRAM or SRAM, a mass storage, e.g., a hard disk or solidstate disk, or the like. The memory 1634 may include suitably configuredprogram code to be executed by the processor(s) 1633 so as to implementthe above-described functionalities of an ICN node, such as explained inconnection with FIG. 12.

It is to be understood that the structures as illustrated in FIG. 16 aremerely schematic and that the UE 1610, the eNB 1620, or the ICN/CCN nodemay actually include further components which, for the sake of clarity,have not been illustrated, e.g., further interfaces or processors. Also,it is to be understood that in each case the memory may include furtherprogram code for implementing known functionalities of a UE, eNB, or ICNnode, respectively. According to some embodiments, also a computerprogram may be provided for implementing functionalities of the UE 1610,the eNB 1620 or the ICN node 1630, e.g., in the form of a physicalmedium storing the program code and/or other data to be stored in thememory 1614, 1624, 1634 or by making the program code available fordownload or by streaming.

Accordingly, the present disclosure provides the following exemplaryembodiments:

According to an embodiment, a method in a system is provided. The systemcomprises an LTE RAN and an ICN/CCN network connected to the LTE RAN.The LTE RAN has a coverage area in which UEs are present. The systemstores correlations between an UE identifier and an entry in a PIT ofthe ICN/CCN, when that UE makes a content request to the ICN/CCN.

According to an embodiment the system uses the correlation to determinewhether a UE, that has made a content request, can be put in idle modeor not.

According to an embodiment the system uses the correlation to page an UEthat has made a content request and was put in idle mode.

According to a further embodiment, a method in an eNB for the LTE RAN isprovided. The eNB has a connection to an ICN/CCN node of the ICN/CCNnetwork, and has a coverage area in which UEs are present. The eNBmaintains a correlation between an identifier of a UE making a contentrequest to the ICN/CCN and an entry in a PIT of the ICN/CCN node forthat request.

According to an embodiment the eNB uses the correlation to determine toleave a UE in connected mode when the UE identifier matches the UEidentifier in the correlation.

According to an embodiment the eNB uses the correlation to initiatepaging an UE that has made a content request and was put in idle mode.

According to a further embodiment, a method in an ICN/CCN node for anICN/CCN network is provided. The ICN/CCN node has a connection to an eNBhaving a coverage area in which UEs are present. The ICN/CCN nodereceives a content request from a UE and an identity of that UE. TheICN/CCN node maintains a correlation between the UE identity and anentry in a PIT of the ICN/CCN node for that request.

According to a further embodiment, a method in an eNB for the LTE RAN isprovided. The eNB has a connection to an ICN/CCN node of the ICN/CCNnetwork, and has a coverage area in which UEs are present. The eNBforwards an identity of an UE making a content request with that contentrequest to the ICN/CCN node. The eNB interrogates with the node if apending request exists for an identity of a UE before putting a UE inidle mode. The eNB putts the UE in idle mode if such a pending requestdoes not exist or leaves the UE in connected mode when such a pendingrequest does exist.

According to a further embodiment, a system is provided. The systemcomprises an LTE RAN and an ICN/CCN network connected to the LTE RAN.The LTE RAN has a coverage area in which UEs are present. The systemfurther comprises a memory which has a table holding correlationsbetween identifiers of UEs making a content request to the ICN/CCNnetwork and an entry of the request in a PIT of the ICN/CCN network.

According to a further embodiment, an eNB for the LTE RAN is provided.The eNB has a connection to an ICN/CCN node for the ICN/CCN network, andhas a coverage area in which UEs are present, the eNB has a memoryhaving said table for holding correlations. The eNB is adapted toperform the methods according to the present disclosure.

According to a further embodiment, an ICN/CCN node for the ICN/CCNnetwork is provided. The ICN/CCN node has a connection to an eNB havinga coverage area in which UEs are present. The ICN/CCN node has a memoryhaving said table for holding correlations. The ICN/CCN node is adaptedto perform the methods according to the present disclosure.

As can be seen, the concepts as described above may be used forefficiently conveying data in a cellular network. For example, theconcepts may be used for enhancing the cellular network with ICNcapabilities and efficiently taking into account mobility and statetransitions of UEs.

It is to be understood that the examples and embodiments as explainedabove are merely illustrative and susceptible to various modifications.For example, the illustrated concepts may be applied in connection withvarious kinds of cellular network technologies, without limitation tothe LTE technology. Further, the illustrated concepts may be applied inconnection with various kinds of ICN enhanced network nodes, withoutlimitation to routers, switches, gateways, or proxies. Further, theillustrated concepts may be applied in connection with various kinds ofICN technologies, without limitation to CCN or NDN. Further, it is notedthat while paging of a UE would typically be done when the UE is in idlemode, it is also possible to page a UE while it is in active mode.Moreover, it is to be understood that the above concepts may beimplemented by using correspondingly designed software to be executed byone or more processors of an existing device, or by using dedicateddevice hardware. Further, it should be noted that the illustrated nodesmay each be implemented as a single device or as a system of multipleinteracting devices.

The invention claimed is:
 1. A method performed by an access node of acellular network, communicatively coupled to an Information CentricNetwork (ICN), the method comprising: receiving a content request from aUser Equipment (UE) having a connection to the access node, the contentrequest being directed to corresponding named content deliverable viathe ICN; linking a UE identifier of the UE to the request, the UEidentifier used at least temporarily within the cellular network toidentify the UE for data delivery via the cellular network; forwardingthe request to the ICN; and performing at least one of the followingoperations: while the UE remains connected to the access node and therequest is pending, extending an inactivity period allowed for the UEbefore triggering disconnection of the UE; or after releasing theconnection to the UE and while the request is pending, initiating pagingof the UE in response to receiving signaling from the ICN indicatingthat the named content corresponding to the request is available.
 2. Themethod of claim 1, wherein extending the inactivity period comprisespermitting the UE to remain inactive for a longer period beforereleasing the connection, than is permitted for inactive UEs withoutpending requests to the ICN.
 3. The method of claim 1, wherein linkingthe UE identifier to the request comprises at least one of: logging theUE identifier locally at the access node, in a listing of UEs havingpending requests to the ICN; or sending the UE identifier towards theICN, in conjunction with forwarding the request to the ICN, for loggingby the ICN.
 4. The method of claim 1, wherein initiating paging of theUE comprises initiating paging of the UE with an indication that thereason for the paging is the availability of the named contentcorresponding to the request.
 5. The method of claim 4, wherein, inresponse to the UE responding to the paging by reconnecting to theaccess node, the method further includes the access node delivering thenamed content to the UE, as received by the access node from the ICN. 6.The method of claim 4, wherein initiating the paging of the UE comprisessending signaling to a mobility management entity in the cellularnetwork that is configured for controlling the paging of the UE from oneor more access nodes.
 7. An access node configured for operation in acellular network, the access node comprising: a first communicationinterface configured to communicatively couple the access node to anInformation Centric Network (ICN); a second communication interfaceconfigured to communicatively couple the access node to User Equipments(UEs) wirelessly; and processing circuitry operatively associated withthe first and second communication interfaces and configured to: receivea content request from a User Equipment (UE) having a cellular radioconnection to the access node, the content request being directed tocorresponding named content deliverable via the ICN; link a UEidentifier of the UE to the request, the UE identifier used at leasttemporarily within the cellular network to identify the UE for datadelivery via the cellular network; forward the request to the ICN; andperform at least one of the following operations: while the UE remainsconnected to the access node and the request is pending, extend aninactivity period allowed for the UE before triggering disconnection ofthe UE; or after releasing the cellular radio connection to the UE andwhile the request is pending, initiate paging of the UE in response toreceiving signaling from the ICN indicating that the named contentcorresponding to the request is available.
 8. The access node of claim7, wherein the processing circuitry is configured to extend theinactivity period by permitting the UE to remain inactive for a longerperiod before releasing the cellular radio connection, than is permittedfor inactive UEs without pending requests to the ICN.
 9. The access nodeof claim 7, wherein the processing circuitry is configured to link theUE identifier to the request by at least one of: logging the UEidentifier locally at the access node, in a listing of UEs havingpending requests to the ICN; or sending the UE identifier towards theICN, in conjunction with forwarding the request to the ICN, for loggingby the ICN.
 10. The access node of claim 7, wherein the processingcircuitry is configured to initiate paging of the UE with an indicationthat the reason for the paging is the availability of the named contentcorresponding to the request.
 11. The access node of claim 10, wherein,in response to the UE responding to the paging by reconnecting to theaccess node, the processing circuitry is configured to deliver the namedcontent to the UE via the access node, as received by the access nodefrom the ICN.
 12. The access node of claim 10, wherein the processingcircuitry is configured to initiate the paging of the UE by sendingsignaling to a mobility management entity in the cellular network thatis configured for controlling the paging of the UE from one or moreaccess nodes, wherein the signaling is sent via the first communicationinterface or a third communication interface of the access node that isconfigured to communicatively couple the access node to the mobilitymanagement entity.
 13. A method by an Information Centric Network (ICN)node configured for operation in an ICN, the method comprising:receiving a request for named content deliverable from the ICN, therequest forwarded to the ICN node from an access node of a cellularnetwork and originating from a User Equipment (UE) connected to theaccess node and including a UE identifier, the UE identifier used atleast temporarily within the cellular network to identify the UE fordata delivery via the cellular network; storing the request as an entryin a Pending Interest Table (PIT), including storing the UE identifierin association with the request; and responsive to the named contentbecoming available, sending signaling to the access node that indicatesthe UE identifier and indicates the availability of the named contentand, responsive to the access node indicating that the UE is no longerconnected to the access node, sending further signaling to the cellularnetwork to initiate paging of the UE by the cellular network fordelivery of the named content, the further signaling indicating the UEidentifier.
 14. An Information Centric Network (ICN) node configured foroperation in an ICN, the ICN node comprising: a communication interfaceconfigured to communicatively couple the ICN node at least to an accessnode in a cellular network; and processing circuitry operativelyassociated with the communication interface and configured to: receive arequest for named content deliverable from the ICN, the requestforwarded to the ICN node from the access node and originating from aUser Equipment (UE) connected to the access node and including a UEidentifier, the UE identifier used at least temporarily within thecellular network to identify the UE for data delivery via the cellularnetwork; store the request as an entry in a Pending Interest Table(PIT), including storing the UE identifier in association with therequest; and responsive to the named content becoming available, sendsignaling to the access node that indicates the UE identifier andindicates the availability of the named content and, responsive to theaccess node indicating that the UE is no longer connected to the accessnode, send further signaling to the cellular network, via thecommunication interface or a further communication interface of the ICNnode, to initiate paging of the UE by the cellular network for deliveryof the named content, the further signaling indicating the UEidentifier.